A laser cutter can be used cut complex and repeatable patterns into plastic for a wide variety of uses. This procedure describes the laser setup and cutting process.
Responses to fires occurring in the laser cutter are categorized by intensity:
1. Small flare-ups the size, area and intensity of a candle flame: Open the hood and simply blow out the flame with air (do not use liquids).
Flare-ups are fires which are not self-sustaining (typically existing for less than 10 seconds in the laser cutter) and are most common. They are well-contained by the machine housing, and may be extinguished without the aid of a fire extinguisher. The laser cutting head and its optical components are resilient against damage from this level of heat and soot, though the lens on the bottom of the cutting head should be cleaned afterwards with lens paper (only!). Lens paper is found in the left-hand shelves above the sink as you enter MC222.
2. Medium fires the size and area less than a closed fist, and which do not reach the PMMA window of the hood in height: Get the fire extinguisher ready in-hand for use. Open the hood and wait ~2 seconds for the cutting head to retract to its start position. Unplug the laser power cable. Keep garments and hair well away from the flame. If a first attempt to blow out the fire with air fails (do not use liquids!), then use the fire extinguisher.
Fires of this size may quickly become self-sustaining to cover the entire material being cut or etched – this has included PMMA sheets in the past. Such fires are typically well-contained by the laser cutter housing, but have an intensity that threatens the cutting head (the red metal piece), breaching of the PMMA window in the hood, and personnel.
3. Large fires bigger than a fist, or which contact the PMMA window of the hood: Get the fire extinguisher ready in-hand for use. Unplug the laser cutter. Open the hood, keep garments and hair well away from the flame, and use the fire extinguisher. If the fire is not immediately extinguished, the fire alarm may be pulled and the lab evacuated according to U of T procedures, at the user’s discretion and common sense.
If a fire extinguisher is used, the incident must be reported within 24 hours using the “Online Workplace Accident/Incident Report for Employees” at http://www.ehs.utoronto.ca/resources/wcbproc/employee.htm. By submitting this form, U of T’s Fire Prevention Services (http://www.fs.utoronto.ca/utfp.htm) will investigate the incident and deliver a fully charged fire extinguisher to the lab.
Materials and Equipment
Before cutting a sample a drawing must be sent to the laser cutter. Once an AutoCAD file has been created the following steps should be done before trying to cut the features using the laser.